Shock absorber



May 8, 1945. s. D..M|TEREFF SHOCK ABSORBER Filed Aug. 20, 1940V gINVENTOR. SERGEI D; MITEREFF BY' QM www ATTORNEY.

Patented May 8, 1945 UNITED STATES PATENT= oFF-ICE kSHOCK Ansofmalilt4 e`Sergei D. Mitereff, PetersburgVa. Application August `20, 1940, SerialNo. 7353,34i-l sciaims. (C1. 18a-tmf l My invention relates to shockabsorbers and has particular reference to shock` absorbers employingelastic or other fluid and adapted to be usedfwith automotive vehicles,landinggears, trailers, etc.`

In my U. S. PatentNo. 2,212,426, issued August 20, 1940, I described onetype of my improved shock vehicle by bolts 3A and having covers 4 and 5fasv tened by bolts' 6. A piston or plunger I slides in absorber andstabilizer employing in its preferred e form compressed air fromfavsource external to the shock absorber, valves being'provided fordistributing the compressed air or otherl fluid in the'I shock absorberso as to inhibit the movements of the supported body with but littleinterference the cylinder ,and` has arod 8 sliding in a sealing `gland9.`v C 4 I Therotherend of therod has anarrn I0 with a ball I Ilpivotallyclamped ina connecting bar .I 2. The other end of the bar I2has a socket .for a ball I3 von the'end of an arm I4 attached toan vaxle I5 of theY vehicle. rIyhe piston rod 8 is conwith the movements ofthe wheels and the axles.

My present invention has for its object tofprovide a shock absorber inwhich an incompressible liquid such as oil can be used, preferablystored in 'a l.reservoir at the shock absorber itself,` and 4 requiringno external supply of oil under pressure for its operation.

My present device is not limited, however, to such passive operationsince it can also be adapted for o peration with' a fluid under pressurefrom asuitable source such Vas an enlarged lubricating' pump of anautomobile, inlet/and drain connections being provided fory this purposein the lsuitable chambers of the device.. `No changesk are required intheshock absorber itself for 0peration with oil under pressure With theexcep- `tion of the necessary connections. The device is alsooperative'without such an external supply of lluid, the passiveoperation being somewhat less efcient. Therefore, the use of oil underpressurefor the operation of the `present device is optional, eMoreover, the pilt and check valves .of the shock absorber are soarranged las to minimize the consumption of oil under pressure, mainlyto reduce the jerk due to sudden application of the stabilizing forceduring the rebound motion of the body of the automobile with 4passiveoperation of the device.

of the device with the axle of the vehicle.

Other objects and advantages of l my invention will be apparent from theaccompanying specification and drawing in Which--v Fig. 1 is a sectionalelevation of my shock ab- My shock absorber is showniin one of itspreferred aforms in Figs. 1, 2 and 3. `It consists ofl a' cylindricalcasing I attached to a frame 2 of a The tension-compressionspring is`optionally used to connectthe pistonrod nected' With'the `axle I5 alsoby means ofjthe tensionecompression spring2I0.` The springZI isinoperative asjlong as the bar I2 is in place. Should the bar I2 beAremoved, the spring 2I0. will then permita somewhat altered and betteroperation of the device` in ystabilizing the body of the vehicle, lin amanner to be explained later. For convenience the vehicle may be definedas a bodyy resiliently supportedon a member, such as `the, axlesfwithwheels,contacting a supporting mediurnsuch as a road surface. lThecylinder 'is filled with `a liquidsuch as oil, mixture of glycerineand.alcohol', etc. The cylinder and plunger actas ashockabsorber forstabilizing the movementsv of the body. My mechanism differs, however,lfromordinary shock absorbers in that the liquid in ,the cylinder is incommunication with an= external supply of the liquid under control ofautomatic valves so that the pressure difference onl eitheruside. of the`cylinderxis .positively control1ed." In' this respect the cylinder andthe plunger representa hydraulic device or force converter ywhichchanges'the relative distribution of .forces caused bythe movements ofthe axle dricalr bore fora sleeve I1. The latter has end walls I8 andI9'with bearings for the Astern 25 of sliding valve 20. Chambers 2| and22 are formed at the ends ofthesleeve I'l and are connected withthevcylinderbore by ducts 23 'and 24. The I stem 25 of the valve 20, hasanenlarged portiony 25 at the top where it passes 'through the wall I8,

the" area'of the shoulder ofthe enlarged portion being equal to the areaofthe lower end 25 of stem 25vpassing through partition I9. vThe valve2,0 .closesr with slight overlap on its inner sides in itsneutralposition ports 26 and 2l which are in communication with the upperA andlower por.-

ti'onsjoi vthecylinder bore by means of" ductsv 28 f andf 29@ The ductsterminate kat acertain Adistance'fromthe covers 4 and 5in/order toprovide 1 a liquidY cushion for the piston at the end of its travel. l li These ports are also `in communication with annular chambers 30 and 3U`closed by check` I valvesj3I-and 3| under tension'of springs 32.

Additional ducts 33 connect the chambers 34 and 35 with a chamber 36which is. in communication with a casing 31 on top of the cylinderhousing I.A

- A relatively tall tube 38 extends from the casing 31 and is closed ontop with a cap 38', vent` holes 39 being vprovided!under" the, cap.v"Acyl-'indfrical ward position so that a.` pressure will be necessary inchamber 13 in order to raise valve member 25, 25', 20 by pressure of theliquid on the lower end` passages A29, 21, '33."'Spring 60 ywill aid inthis low 'liquidto' flow intofchamber 'Iiftmough pas:

weight lill'y slides in tlie'tube, being 'supported `by a spring 4Iresting on a horizontal wall 42. Holes 43 are provided in the wall 42for oil or'similar" liquid inchamb-er 44 which lls part of the tube 3.8,casing 31, chamber 36, chambers 34 and 35, rand the cylinder I. Theweight 40 a" rodi 4'5 1 with a plunger 46 lsliding i-n.a smaller tube 41tted centrally inthe wall 4'2;` The plunger has a hole 48 for the oiland issattache'd at; 49j to? the upper end of a helicalzspring 5uwhoseother end is attachedto a pl'ate's'r on trie' upperend' ofthe downthrough the-springin. The plateif rests ron a' luel 53' on' an. arm'54'pivotedfat 55E toi a post bore 5'9 in" the" body ofthe casing'extension. l 6 and f supported 'on' a spring lill.` The otne'rend of thel valve' stem'l.' plate' 51|l is. connectedby' loe'll lows 5:2"withthelower en'd of the' 'inner tube. s o i that the weight 40 can move the rValve 20 up ory movement of weight 51. Check valve 3I will alsag'es'2*6, 28, upon rebound'. If p'iston`1 should travel past neutral on itsrebound vstroke the sec# ond rebound or return to'neutral will againbeylirriliial-ly opposed since the dashpot` controlled weight 40 will lagin `its upper position and thus l y"isieee's'sitatefa greater pressurein chambers 12 2| to lowerr valve' stem 25. Thus the initial up-Wardmovement of piston 1 is not appreciably checked but an increasedchecking action occurs` y asupward movement of piston 1 increases rela-7` Initial downward or rebound tive' to' casing' I'. l v movement of'piston ll isr checked andv this' cheekingy aotioris relievedv asi therebound progresses. Arly" second oriz'mforerebound movement kwilliloeinitially cheeked and' tnenireli'eved'asin tlie 'first The relativelyweak tensi'o'riicorripression.spring 5i) under' the' plunger46"`Will`eX`ert a downward pressure loii the Bottom ofthe tuloeforontne,vvplate 5l, this* foree "ori pressure vbeing.proportional to the'absolute vertical' displacements" of the body' of the vehicle. AAtth'esame time the weight' 51`wil`l produce ai downward reaction' forceproportional to' the vertical absolute acceleration on'l a `post 10extending' fromthec'over 5,"thje- I n l l y Y 4 the Weight j are'stronglyl dafnped'byrfrictn of otherv end being pivoted at TI" td therod" Un'- valve 20 vrenflain's rin' itsy neutral" position',V and theweightA 40' remains Yi'ntlie, redui'libriun'i on' Athe slots 40"toffacili'tate itsl movement' in' the oi-l be-y Upom upward movement*off a-xlef I 5' the vehicle wheelstrikes vanrv obstruction, piston; 'Fismoved' upwardflthroirgnlink mf andfrce's' q' uid through passage .213against shoulder einher tliru'stoirr the plate'A 5f; 'Iftli'e movementsor surrounding'oil",` the relative1 displ'a'oerrientA of,y the theymoment' un'der consideration; This ,ifsy b'e"-.

causel with*l strong liquid viscose resistance.' the 'weight 40 wil-1"movejin space almost tnes'ame' dis? tance as traversed by' the b od'y'of the' vehicle. Therefore;thejaocelerationqof,the weight 40 will beveryy'vnearlv4 equal to the aece'l'era'tiorroi the l i body." Thetension'of'tlf'le long supportingsprng et iva'rying' but little; and theresistanceof the pIurIgerWBand-tlie springt wbei'n'g' snial'f,.jth'eacceleration reaction of" th'ejweight' 4llywil1 be this willincreasethe' pressure. yinchalnbe'zlg: 12ga-'ZI necessary to lowervalve-sterrr 25,. in proportion toy the.` relative distance the-axleI5,- `:movesA up'- wardly with; respect to. frame 2f Check valve 3-|springainerti'a weights. 5:1 ande4IL-will.move

lmove downwardly .rapidly, against.l the actie-rtY 'ofr spring' gjwhichi's then. compressed by linkage slowly because itsmovement is. retarded'bydaslitherefore', retarded 1 because., weigh slowed by' dashpot 475,148returningyto itsupf ward position' relative to tube? .381 thus"yielclably lfiol'dingl valve member, 25"; @finit-5f. down;

' pot '41,481v Rebound movement. oflaizler A`I5Ais 14u Awur; te'

"from" on'e Side of the weight v4t'o" another Athrough 'totheacceleration ofi the weight 4,0" in respect' to the tope es'. :Thereforethe;l magnitude' 'of the relativedispfaeemerit'between the weight 4faiidthe tute allA will' be proportional' to the acceleration' of' tlieweight 40' 38 whileas just-was explained', the relative-dfsplarcenvrentisA proportional' in 'thi'scasetb' the"Y ab? and' 'for'k thatm'atter'oftrie n or .trie Body? 2,375,377 As before, the reactive force or theweight t1` Therefore, with the assumed upward acceleration the plate 5land the valve discs 2D and 20 will be moved downwards overlapping andopening ports 21 and 26. Since at the beginning of upward impact due toa raised spot on the road, the axle I5 and piston move upwards fasterthan the body, the oil in chamber 12 will be compress-ed by the piston 1but no appreciable pressure can be built in chamber 12 because oil isfree to escape from it through ports 28, 26, bore 34, and port 33 intolow pressure chamber 36.

At the same time no vacuum can be formed behind the receding piston inthe chamber 13 suspension springs of the vehicle by 'theaddtional upwardforce acting `on stem 25 generated `by the compression of 'spring SII asone piston 1 because oil will be admitted from chamber 36 through checkvalve 3|, circular chamber 30 and the port 29.

As soon as the raised spot on the road surface begins to decline, thepiston 1 will start to lag behind the body which is still moving upwardschamberY 13 will now be compressed but it cannot escape from it as longas valve d isc 20 is in downward position since check valve 3l preventsthe reverse iiow.

However, as soon as pressure in the chamber 13 is built sufficientlyhigh it will move valve 20 upwards by acting on the lower plunger 25through port 24 and bore 22, thus permitting oil in the chamber 13 toescape into space 3B through duct 29, ducts 21, bore 35 and duct 33.

It will be clear that in order to move valve 20 upward in opposition todownward forces acting on the plate 5I proportional to the accelerationof the body, the pressure in the chamber 13 will havel to be alsoproportional to the acceleration of the body.

I'hus the acceleration component will have the eiect of increasing themass of the body, thus .lengthening its natural period of oscillation.

overcome by substituting tension-compression spring 2I0 connecting theaxle I5 with the rod 8 for the link l2, which softens this jolt.

The weightl 51 represents an inertia component of the system. It issupported on the spring 60 which is in turn supported on the axle I 5through the links 62, 66 and 68. The object of this arrangement is toincrease the average oil pressure in chamber 12 at greater deection ofthe as the result of original impact. `The oil in the is moved upward. y

It is understood that my shock absorber may be further modied withoutdeparting from the spiritof'my invention as set forth in the appendedclaims.

I claim as my invention: w i

l. A shock absorber for'a body resiliently sup-y portedr on a membercontacting a supporting medium, the body and the member being. adaptedto have a motion of translation over the supporting medium, a cylinder,a plunger slidably fitted in the cylinder, the plunger and the cylinderbeing connected to the body and to the member for relative movementtherebetween, the cylinder being adapted to contain a liquid, ayieldably y supported movable inertia element dampened by iiuid frictionresponsive to dynamic properties of the vertical movements of the body,a source of the liquid for the cylinder, a valve capable of restrainingthe iiow of the liquid from thecylinder, meansto operateA the valve bythe said inertia element pressurefcontrolled portions on the plunger'acteduponby the differential pressure across the `plunger to oppose theflow restraining action of `said valve, and check valves for admittingthe liquid from the source into the to'have a motion of translation overthe sup-r porting medium, a'cylinder, a plunger slidably fitted in thecylinder, the plunger and the cyl- 'inder being connected to the bodyand tothe member for relative vmovement therebetween, the cylinder beingadapted to contain a liquid, a source of the liquid for the cylindenavalve controlling the movement of the liquidbetween its y source and thecylinder, means to move the valve by the pressure in the cylinder infront of' the advancing piston for opening' thecommunication between thecylinderjin front of the piston and the source ofthe liquid forreleasing the pressure infront of the piston, check valves for admittingthe liquid from the source-intothe Acylinder back of the plunger, andsupplementary means to actuate the first said valve in proportion tothe' movement of the plunger in respect to the cylinder.

3. A` shock absorber for a body resiliently supported on a membercontacting a supporting medium, the bodyfand the member being adapted tohave a `motion of translation over the supporting medium, a cylinder, aplunger slidably fitted in the cylinder, the plunger and the cylinderbeing connected to the body and to the member for relative movementtherebetween, the cylinder being adapted to contain a liquid, a movabledampened inertia element responsive to dynamic propertiesy of thevertical movements of the body, a'source of the liquid for the cylinder,

' a valve controlling the now of the liquid from the source to thecylinder, means to operate the valve by the said inertia element, and bythe pressure in the cylinder in front of the advancing piston, and acheck valve to admit liquid into the `cylinder head of the plunger.

SERGEI D. MI'IEREFE.

